This paper discusses measures to improve retaining rate of injected water in reservoir in late stage of oilfield development through analyzing the relationships between retaining rate of injected water and the ratio of total oil produced to OOIP, pressure, and fluid productivity index.

This paper analyzed the variation of the fluid productivity index and oil productivity index in Wenmi oilfield and their affected factors in which include the effects of crude viscosity and starting pressure gradient on these two indexes with changes of water-cut.

The main parameters of optimized design to fracture are dimensionless fluid productivity index,dimensionless proppant number and dimensionless fracture conductivity,and it is the key that understands the relationship of these to optimum design of hydraulic fracturing.

In consideration of reservoir percolation mechanical theory and productivity evaluating theory of well testing analysis, the concepts of layering percolating flow rate and layering production index are introduced The layering productivity evaluating principles and methods are described The application example shows that the evaluating result is basically consistent with the productio

The relationships between productivity index and producing pressure drop of the producing wells of different producing formation patterns are established through studying the change of oil producing capacity of the producing wel.

Based on the theory of energy balance for liquid at pseudo-steady state, the paper establishes a new mathematic method of determining productivity index and reservoir pressure of oil wells that creates the objective function by using correspondence of surface performance data and unknown formation parameters which increases the practicability of the model greatly.

The relationship of productivity index and inflow performance of steam drive wells is established based on compound reservoir model of different heated area of wells in steam drive pattern.